Richards, L.Ismail, FarzanaNel, J.Omar, Shaheed Vally2025-06-252025-06-252024-07Richards, L., Ismail, F., Nel, J. et al. 2024, 'Missed rifampicin and isoniazid resistance by commercial molecular assays', South African Medical Journal, vol. 114, no. 7, pp. 14-16. https://doi.org/10.7196/SAMJ.2024.v114i7.1779.0256-9574 (print)2078-5135 (online)10.7196/SAMJ.2024.v114i7.1779http://hdl.handle.net/2263/102997Drug-resistant tuberculosis (TB) has poor outcomes unless resistance is detected early, ideally by commercially available molecular tests. We present a case of occult multidrug-resistant TB where both rifampicin and isoniazid resistance were missed by molecular testing and were only identified by phenotypic testing.en© 2024 L Richards, F Ismail, J Nel, S V Omar. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Tuberculosis (TB)Drug resistanceDiagnosisMutationsMolecular markersChallengesDrug-resistant tuberculosis (DR-TB)Article